1. Field of the Invention
This invention relates to the area of digital orthodontics and more particularly to methods of using digital data to fabricate appliances.
2. Description of the Related Art
Orthodontics is the area and specialty of dentistry associated with the supervision, guidance and correction of malpositioned teeth into proper locations. Orthodontic treatment can be useful in correcting defects in a patient's bite (also called occlusion) along with promoting better hygiene and improving the overall aesthetics and health of the teeth.
During the course of such treatment, an orthodontic professional may direct the patient to wear a customized laboratory appliance to achieve a particular treatment goal. For example, such an appliance may be needed to reposition the patient's mandible or expand the palatal arch. Other laboratory appliances, such as Hawley retainers, are very commonly prescribed to provide tooth immobilization at the conclusion of treatment. These laboratory appliances are typically fabricated using a labor intensive process carried out by a skilled technician. Early appliances were hand crafted by practitioners on a physical dental model made from plaster, or orthodontic stone. The physical dental models, in turn, were typically cast from an impression of a patient's dentition made from a suitable impression material, such as alginate or polyvinylsiloxane (PVS). Techniques of dental mold making are well known.
Today, laboratory appliance providers such as commercial dental laboratories continue to produce these appliances by applying and shape setting plastic and/or custom bent wires to an orthodontic stone model of the patient's dental structure. When a laboratory appliance is needed, a stone model can be prepared using standard dental impressions taken at the site of an orthodontic (or dental) professional and then the model transported by mail to the dental laboratory along with an order form to request the fabrication of a laboratory appliance. While this workflow is effective, transporting the physical dental model to the laboratory incurs a delay as well as a shipping cost. Moreover, the process of creating an alginate impression and pouring a stone model is time consuming for the staff of an orthodontic practice and is often unpleasant for the patient.
The preparation of impressions followed by the casting of stone models and the shipment of stone models to an orthodontic or dental laboratory to manufacture a laboratory appliance remains a largely manual process. A method which improves upon the efficiency and reliability of current methods would be welcome by both orthodontic professionals and appliance fabricators.